<!DOCTYPE html>
<meta charset="utf-8">
<link rel="author" title="Ting-Yu Lin" href="mailto:tlin@mozilla.com">
<link rel="author" title="Mozilla" href="https://www.mozilla.org/">
<link rel="help" href="https://drafts.csswg.org/css-break/#break-decoration">
<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1564726">
<link rel="match" href="../reference/ref-filled-green-100px-square.xht">

<style>
.multicol {
  column-count: 2;
  column-gap: 0;
  column-fill: auto;
  inline-size: 100px;
  block-size: 100px;
  background: red;
}

.container {
  padding: 5px 0;
  border-block: 10px solid green;
  box-decoration-break: clone;
  background: green;
}

.child {
  block-size: calc(70px + 70px); /* 1st column + 2nd column */
  background: green;
}
</style>

<!-- The container's block-size is auto, so the available column block-size
     reserved for the child is 70px in every column. -->

<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
<div class="multicol">
  <div class="container">
    <div class="child"></div>
  </div>
</div>
